Wikipedia's Highest and Best Use
Wikipedia is virtually useless as a source for anything controversial, such as global warming. However, it is absolutely fabulous as a dictionary of pop culture. Where else can you find 5500 words on h4x0r l33t speech?
As someone who once started a book article in Wikipedia and gave up after realizing that no one but me (and very few others) was interested in accuracy, I have to agree with your opinion. Pity, really, it was such a good idea.
In fact, by far the best source of popular culture is Encyclopedia Dramatica: http://encyclopediadramatica.com/Main_Page
Warning: The site is obsessed with loading pages with disgusting pornographic images. Needless to say, it is Not Safe For Work. If you can stomach them, however, you're not going to find any better source for the origins of memes.